The most used resin for violins and bows
Rosin is a solid resin derived from the oleo-resin (crude turpentine) exuded by various species of pine tree. Rosin is extracted by heating the oleo-resin to vaporise the essential oils (spirit of turpentine), or through a naphtha solvent process. Rosin is mainly produced in Portugal and Brazil but Indonesia, northern Vietnam, southern China, the US, Mexico and France are also producers.
Rosin is sold as a semi-transparent solid ranging in colour from yellow to black and has a faint odour of pine. The commercial grades range from A (the darkest) to K (yellow red), M (yellow brown) and N (deep yellow), through to superior WG ("Window Glass", yellow) and WW ("Water White", slight yellow) sold here by Grandi Liutai Italiani. Rosin is brittle and easily crumbled at room temperature, but melts at around 100-120 °C and is highly flammable. Rosin dissolves in alcohol, benzene, chloroform and ether. It is also soluble in spirit of turpentine and turpentine substitute.